Shoe-sewing machine



F. ASHWORTH.

SHOE SEWING MACHINE.

APPLICATION FILED JAN. 3. I916.

Patented Feb. 3, l920.-

74ZZzzava UNITED STATES PATENT OFFICE.

FRED ASHWORTH, or BEVERLY, MASSACHUSETTS, AssIeNon, BY MEsNE ASSIGNMENTS,

To UNITED SHOE MACHINERY CORPORATION, or PLATERSON, NEW JERSEY, A con- IORATION OF NEW JERSEY.

'si'ioE-SEw Iive manna.

To all whom'it'may concern.

Be it known that I, FRED ASHWORTH, a citizen of the United States, residing at Beverly, in the county of EsseX and Comnionwealth of Massachusetts, have invented certain new and useful Improvements in Shoe-Sewing Machines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to Which it appertains to make and use the same.

The invention relates to shoe sewing machines, and more particularly to presser foot mechanisms for such machines. 7

One object of the present invention is to provide shoe sewing machines having a work support and a presser foot for posi tioning the work relative to the sewing mechanism during the sewing operation with an improved clamping device for the presser bar which will act to clamp the presser bar at certain times during each cycle of operation, and hold the same in a more certain and reliable manner than such devices which have heretofore been employed on this class of machines.

In certain classes of shoe sewing machines, such asmachines of the 'so-called McKay type, the presser bar is lifted during each cycle of operation to raise the presser foot, and another object of the invention is to provide shoe sewing machines of this class with improved mechanism for clamping and lifting the presser bar a substantially uniform distance during each cycle.

It is to be understood, however, that the invention in its broader aspects is not limited in its application to a machine in which the presser bar has a movement during each cycle of operation to lift the presser foot, but that it may be embodied with advantage in machines in which the presser bar is clamped and held in a stationary position at a certain time during each cycle.

The invention will be readily understood from an inspection of the accompanying drawings illustrating a. machine embodying the invention in its preferred form, and the following detailed description. In the drawings Figure 1'is a view in side elevation of the head of a shoe sewing machine embodying the invention;

Specification of Letters Patent.

ing the greater part of the Patented *Feb. 3, 1920.

m1 this application filed January Fig. '2 is a detail view partly in plan and partly in horizontal section taken "substantially on the line of Fig. 3;

Fig. 3 is a detail view in vertical section Illustrating a portion of the mechanism for lifting the presser foot; and

Fig. 4 is a detail sectional view takensubstantially on the line of Fig. 3.

The shoe sewing machine illustrated in the "drawing comprises a vertically recipro eating straight "hook needle and devices cooperating therewith to form a chain stitch seam and a rotatable horn upon which the shoe is supported during the sewing operation, such machines being known in the art as machines of theMcKay type. In the drawings the straight hook needle is indicated at 2, and the work feeding awl at 4, both of which parts have the same 0011- The work supporting horn'of the machine is indicated at 6, and the presser Pfo'ot jeooperating therewith at 8. In the present embodiment of the invention the horn is vertically immovable, and the presser foot is arranged for vertical movement with relation to the horn to accommodate work of varying thicknesses. 7

During each cycle of operations of the machine, starting just after. the needlehas finished its upward stroke, the presser foot is lowered into engagement with the work, is pressed yieldinglyagainst the work durcycle of operatlons, accommodating itself to the thickness of the work, and is lifted just before the work'is fed to permit the work to be ad vanced between the presser foot and the horn. The presser foot is secured to the lower end of a presser bar 10 which is arranged'to slide vertically in a suitable guide formed in the lower plate of the'frame of the head of the machine. A cap or sleeve 12 arranged to slide in a guide in the upper plate of the frame of the vhead of the machine is secured to the upper end of the presser bar, and the upper end of the cap is engaged by the forwardly extending arm of a coiled spring 14 which acts yieldingly to hold the presser foot in engagement with the work. The downward movement of the presser foot when no work is in the machine is limited by the engagement of the lower end of the sleeve 12 with a bracket 16 provided with a perforation through which the presser bar passes, and adjustably secured by screws 18 to the side of the machine frame.

The mechanism for lifting the presser foot during each cycle of operations to permit the work to be fed, comprises a clamping device for the presser bar which during each cycle is actuated to clamp the presser bar, and is then moved bodily to lift the presser bar a substantially uniform distance regardless of its vertical position. This clamping device is illustrated in detail in Figs. 2, 3 and 4, and comprises a nut 20 engaging screw threads 22 of comparatively steep pitch cut on the presser bar, and a U- shaped spring clamping block 24 surrounding the nut, which may be engaged with the periphery of the nut to lock the nut from rotation on the presser bar by contracting the rear ends of the clamping block. The nut when not engaged by the clamping block is free to turn so that it then offers substantially no resistance to a vertical movement of the presser bar, or to a relative axial movement of the nut and the bar. The nut 20 and the clamping block 24 are supported by a sleeve 26 surrounding the presser bar, which sleeve is provided with a recess to receive both the nut and the block, as shown in Fig. 3. The upper end of the supporting sleeve is engaged by a coiled spring 28 surrounding the presser bar and confined between the upper end of the sleeve and the lower face of the bracket 16. This spring acts to hold the sleeve in its lowermost position, the downward movement of the sleeve being limited by the engagement of its lower end with a portion of the machine frame. In the operation of raising the presser foot, the nut 20 is first clamped by the clamping block 24, and thereby locked from turning movement on the presser bar, and the nutclamping block and sleeve 26 are then lifted bodily to impart an upward movement to the presser bar. To enable the forward ends of the clamping block to be contracted to clamp the nut 20, the ends of the block are formed with oppositely inclined faces 30, as shown in Fig. 4, and an actuating lever 32 is pivoted by means ofa pin 34 on the sleeve. 26, said lever being constructed in the form of a yoke, the arms of which embrace the clamping block as shown in Figs. 2 and .4. The arms of the lever 32 are respectively provided with oppositely inclined cam faces 36 which, during the upward swinging movement of the lever 32 from the position shown in Figs. 3 and 4, engage the inclined faces 30 formed on the forward ends of the clamping block to contract or bring together the ends of the clamping block, and thereby lock the nut securely from rota tion on the presser bar. The upward swlngmg movement of the lever 32, is limited by its engagement with the clamping block after the arms of the block have been contracted to lock the nut on the presser bar, and the presser bar is then raised by the bodily upward movement of the lever Which lifts the sleeve 26, the clamping block and the nut. After the work has been fed by the feed point the lever 32 is lowered bodily, allowing the presser foot to be depressed by the action of the coiled spring 14. lVhen the presser foot engages the work, or when the lower end of the sleeve 26 engages the frame, the lever 32 swings downwardly about the pivot pin 34, allowing the ends of the clamping block to expand and unlock the nut so that it can turn freely on the presser bar. The unlocking of the nut leaves the presser bar and the clamping device therefor free for relative movement, so that the lower end of the sleeve 26 is then engaged with the frame by the action of the coiled spring 28, and the presser foot is held in yielding engagement with the work by the spring 14. It will be noted that the clamping devices at the time that the presser bar is clamped always have the same vertical position, regardless of the position of the presser bar, as determined by the thickness of the ork, and that the presser bar is lifted always the same distance.

The lever 32 is actuated to clamp the presser bar and then to lift the presser bar during each cycle of operations of the machine by the movement of a bell crank lever 38 pivoted at 40 on the frame of the machine, and having its forwardly extending arm connected by an adjustable link 42 with the lever 32. The other arm of the bell crank lever is provided with a cam roll 44 which engages a cam groove 46 in a cam disk 48 mounted on the main shaft 50 of the machine.

Having explained the nature and object of the invention, and having specifically described a machine embodying the machine. in its preferred form, what is claimed is l. A shoe sewing machine, having, in combination, stitch forming devices, a presser bar, a presser foot, clamping mechanism for the presser bar comprising a springclamp embracing the bar, an actuating member having opposed cam faces for engagement respectively with the ends of the spring clamp to move the same, and means for moving the actuatingv member to actuate the ends of the clamp to clamp the presserbar.

2. A shoe sewing machine, having, in combination, stitch forming devices, a presser foot, a presser bar, clamping mechanism for egal the presser bar comprising opposed clamping jaws arranged upon opposite sides of the bar and having a relative movement in a plane transverse to the axis of the bar, an actuating member arranged to engage the ends of both of the clamping jaws and hawing a cam face for engagement wit-h the end of one of the jaws to move relatively the jaws, and means for moving the actuating member to actuate relatively the jaws to clamp the presser bar. 1

3. A shoe sewing machine, having, in combination, stitch forming devices, a presser foot, a presser bar, clamping mechanism for the presser bar comprising opposed clamping jaws arranged on opposite sides of the bar and each having a movement in a plane transverse to the axis of the bar, an actuating member having opposed cam faces for engagement respectively with the ends of the jaws to move the jaws, and means for moving said member to actuate the jaws to clamp the bar.

4. A shoe sewing machine, having, in combination, stitch forming devices, a presser foot, a presser bar, a clamping mechanism for the presser bar comprising opposed clamping jaws arranged on opposite sides of the bar and having a relative movement in a plane transverse to the axis of the bar, an actuating member arranged to engage the ends of both of the clamping jaws and having a cam face for engagement with one of the jaws to move relatively the jaws, and means for moving the actuating member to actuate relatively the jaws to clamp the presser bar and then to move the jaws bodily to lift the bar.

5. A shoe sewing machine, having, in combination, stitch forming devices, a presser foot, :1 presser bar, clamping mechanism for the presser bar comprising a spring clamp embracing the bar and having opposed clamping jaws, an actuating member having opposed cam faces with which the ends of the spring clamp respectively engage, and means for moving the actuating member first to relatively actuate the jaws of the clamp to clamp the bar and then to move the clamp bodily to lift the bar.

6. A shoe sewing machine, having, in combination, stitch forming devices, a presser foot, a presser bar, clamping mechanism for the presser bar comprising opposed clamping jaws arranged upon opposite sides of the bar, means for relatively moving the clamping jaws to clamp the bar and for moving the jaws bodily to lift the bar.

7 A shoe sewing machine, having, in combination, stitch forming devices, a presser foot, a presser foot bar, means for engaging the presser foot with the work, means for raising the presser foot a substantially uniform distance during each cycle of operations comprising a nut threaded on the a spring clamp surround a device for actuating the nut from rotatlon on the presser foot bar,

ing said nut, and clamp to lock the presser foot bar.

8. A shoe sewing machine, having, in combination, stitchforming devices, a presser foot, a presser foot bar, means for engaging the presser foot with the work, means for lifting the presser foot a substantially uniform distance during each cycle of operations comprising a nut threaded on the presser foot bar, a spring clamp surrounding said nut, inclined faces formed on the ends of the clamp, a device embracing the ends of the clamp and arranged to engage the inclined faces thereon to actuate the clamp and thereby lock the nut from rotation on the presser foot bar, and means to actuate said device.

9. A shoe sewing machine, having, in combination, stitch forming devices, a presser foot, a presser foot bar, means for engaging the presser foot with the work, means for lifting the presser foot a substantially uniform distance during each cycle of operations comprising a nut threaded on the presser foot bar, a spring clamp surrounding said nut, a device for actuating the clamp to lock the nut from rotation on the bar, and presser foot lifting means conn'ected with said device and arranged to actuate the device to lock the nut on the presser foot bar as the presser foot is lifted.

10. A shoe sewing machine, having in combination, stitch forming devices, a presser foot, a presserv bar, a support through which the presser bar passes, clamping mechanism for the presser bar comprising opposed clamping jaws mounted on the support upon opposite sides of the bar and having a relative movement in a plane transverse to the axis of the bar, an actuating member for moving relatively the jaws to clamp the presser bar relatively to the support, and means for moving the actuating member.

11. A shoe sewing machine, having in combination, stitch forming devices, a presser foot, a presser bar, a support through which the bar passes, a clamping jaw movably mounted in a recess in the support to move in a plane transverse to the axis of the presser bar toward and from the bar, a device having a cam face for moving. the clamping jaw, and means for reciprocating said device during each cycle of operations.

12. A shoe sewing machine, having in combination, stitch forming devices, a presser foot, a presser bar, a support through which the presser bar passes, a nut threaded upon the presser bar and arranged in a recess in the support, a clamping jaw fitting closely in the recess in the support and movable therein in a plane substantially perpendicularto the axis of the presser bar into and 3 out of engagement with the nut, and an actuating member for actuating the clamping jaw to clamp the nut relatively to the support during each cycle of operations.

5 13. A shoe sewing machine, having in combination, stitch forming devices, a presser foot, a presser bar, a support through which the presser bar passes, a nut threaded the presser bar.

FRED ASHWORTH 

